Deployment of a site can be cumbersome. One problem is to know what type of antenna to use and prediction of antenna usefulness in a system. In future access systems, it is likely that advanced concepts such as Multiple Input Multiple Output (MIMO) and Beam Former (BF) will become standard ways of transmission. To this end, it is clear that it would be advantageous to know which transmission scheme to use for specific users. A channel with flat spatial spectra is good for MIMO transmission. On the other hand a spatial spectrum with peaky spatial spectra is better for BF transmission.
Advanced antenna solutions enabling MIMO transmissions or BF transmission, are well known. However, today there is no direct method to determine which of these two are more suitable. Indirect methods such as observing Channel Quality Index (CQI) or Signal to Noise Ratio (SNR) may be used. The obvious drawback is that these observations do not provide information on the spatial spectral properties. Consequently, a report on low SNR at a position may result in using BF for a channel that has a large Power Azimuth Spread (PAS). MIMO transmission depend on if the channel is spatially flat (white). In the event of a spatial flat channel the channel matrix singular values are equally sized. The Singular Value Decomposition of an estimated channel is one way to determine the singular values.
Computing channel estimates and SVDs is costly and relies on pilot sequences. These sequences are not present in all packages implying that channel estimation can only be made at certain time instances.